Error when deploying 2nd gen Firebase Cloud Function

This Firebase blog post says that Gen 2 functions are available from 7/31/23, but when I try to firebase deploy one of them, I get this error:

Error: [callGroupRTDBSetup(us-central1)] Upgrading from GCFv1 to GCFv2 is not yet supported. Please delete your old function or wait for this feature to be ready.

A few days ago I recreated my project from scratch, doing firebase init all over again. I think the only thing I might not have updated is Node.js. Today I ran npm update -g firebase-tools because it told me there was an update available. I also restarted my computer. My firebase --version is now 12.4.7.

import {onCall} from "firebase-functions/v2/https";

exports.callGroupRTDBSetup = onCall({cors: true}, async (req) => {
  try {
    const groupID = req.data.groupID;
    const adminUID = req.data.adminUID;
    const adminUsername = req.data.adminUsername;
    const createdTimestamp = req.data.createdTimestamp;

    await setGroupAdminRTDB(groupID, adminUID, adminUsername, createdTimestamp);

    await addMemberRTDB(groupID, adminUID, adminUsername, createdTimestamp);

    return {
      returnVal: 1,
      returnMsg: "callGroupRTDBSetup success!",
    };
  } catch (error) {
    throw new HttpsError("invalid-argument", "Error: " + error);
  }
});